This invention relates to electric furnaces of the type utilizing insulation modules. More particularly, this invention relates to insulation modules to be mounted at the furnace roof and having means to support electric heating elements for the furnace.
In U.S. Pat. No. 3,500,444 to W. K. Hesse, et al, a lightweight ceramic fiber insulation is disclosed. Due to energy saving advantages, such ceramic fiber insulation is often used in place of more dense fire brick for furnace linings. Many of the insulation applications are for oil or gas fired furnaces. However, such insulation may also be used with electric heating elements as shown in the Hesse, et al patent and in the Werych U.S. Pat. No. 3,870,861. In those patents electric heating coils are embedded in the ceramic fiber.
An often preferred form of electric heating element for use in furnaces is that which has become known as the rod overbend type of heating element. Such a heating element is formed of a single, substantially rigid rod suitable for conducting electricity and thereby becoming heated. To form an overbend element, a rod is bent around forming rods into successive parallel passes of a heating element. An example of such a rod overbend heating element is shown at 42 in FIG. 4. Although named for the specific preferred method of forming the successive pass configuration of the rod overbend element, the element may be formed by any of a number of other methods.
With the increased use of ceramic fiber insulating modules to insulate the roofs as well as walls of furnaces, it has become desirable to provide appropriate means for supporting a rod overbend element below a ceramic fiber furnace roof. An object of this invention is to provide such a heating element support, especially one which is structurally simple yet quite durable.
It is a further object of this invention to provide such a heating element support which provides for quick mounting and quick release of rod overbend heating elements so that the heating elements may readily be replaced as necessary without damaging the furnace.